head.S (1690B)
1/* 2 * Startup glue code to uncompress the kernel 3 * 4 * (C) 2017 Helge Deller <deller@gmx.de> 5 */ 6 7#include <linux/init.h> 8#include <linux/linkage.h> 9#include <asm/asm-offsets.h> 10#include <asm/page.h> 11#include <asm/psw.h> 12#include <asm/pdc.h> 13#include <asm/assembly.h> 14#include "sizes.h" 15 16#define BOOTADDR(x) (x) 17 18#ifndef CONFIG_64BIT 19 .import $global$ /* forward declaration */ 20#endif /*!CONFIG_64BIT*/ 21 22 __HEAD 23 24ENTRY(startup) 25 .level PA_ASM_LEVEL 26 27#define PSW_W_SM 0x200 28#define PSW_W_BIT 36 29 30 ;! nuke the W bit, saving original value 31 .level 2.0 32 rsm PSW_W_SM, %r1 33 34 .level 1.1 35 extrw,u %r1, PSW_W_BIT-32, 1, %r1 36 copy %r1, %arg0 37 38 /* Make sure sr4-sr7 are set to zero for the kernel address space */ 39 mtsp %r0,%sr4 40 mtsp %r0,%sr5 41 mtsp %r0,%sr6 42 mtsp %r0,%sr7 43 44 /* Clear BSS */ 45 46 .import _bss,data 47 .import _ebss,data 48 49 load32 BOOTADDR(_bss),%r3 50 load32 BOOTADDR(_ebss),%r4 51 ldo FRAME_SIZE(%r4),%sp /* stack at end of bss */ 52$bss_loop: 53 cmpb,<<,n %r3,%r4,$bss_loop 54 stw,ma %r0,4(%r3) 55 56 /* Initialize the global data pointer */ 57 loadgp 58 59 /* arg0..arg4 were set by palo. */ 60 copy %arg1, %r6 /* command line */ 61 copy %arg2, %r7 /* rd-start */ 62 copy %arg3, %r8 /* rd-end */ 63 load32 BOOTADDR(decompress_kernel),%r3 64 65#ifdef CONFIG_64BIT 66 .level PA_ASM_LEVEL 67 ssm PSW_W_SM, %r0 /* set W-bit */ 68 depdi 0, 31, 32, %r3 69#endif 70 load32 BOOTADDR(startup_continue), %r2 71 bv,n 0(%r3) 72 73startup_continue: 74#ifdef CONFIG_64BIT 75 .level PA_ASM_LEVEL 76 rsm PSW_W_SM, %r0 /* clear W-bit */ 77#endif 78 79 load32 KERNEL_BINARY_TEXT_START, %arg0 /* free mem */ 80 copy %r6, %arg1 /* command line */ 81 copy %r7, %arg2 /* rd-start */ 82 copy %r8, %arg3 /* rd-end */ 83 84 bv,n 0(%ret0) 85END(startup)